This invention relates to electro-optic devices and in particular to optically addressed electro-optic devices.
EP-A-488455 describes an electro-optic device which comprises a substrate carrying an addressable matrix device such as a liquid crystal display device or an image sensor. The rows and columns of the matrix array of display pixels or imaging elements are accessed by supplying signals along row and column conductors using an electro-optic switching arrangement which comprises photosensitive elements provided on the substrate carrying the matrix array. In the arrangement described in EP-A-488455, the photosensitive elements are driven by a linear array of light emitting devices such as light emitting diodes or the like. Each row (or column) conductor is associated with a unique pattern of photosensitive elements with each photosensitive element being located at the intersection of the row (or column) with a column (or row) conductor so that by activating a given set of the linear light emitting devices a given set of column (or row) conductors and the associated photosensitive elements are illuminated causing the photosensitive elements to conduct. Each unique pattern of illumination of the linear light emitting devices corresponds to a unique arrangement of photosensitive elements and accordingly when a selected given set of light emitting devices is activated all of the photosensitive elements associated with a unique row (or column) conductor will conduct so coupling that row (or column) conductor to the associated drive circuitry. Such an arrangement enables a reduction in the number of components and allows there to be comparatively few external connections to the electro-optic device.